Valproic acid exhibits anti-tumor activity selectively against EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer via induction of ErbB family members-targeting microRNAs

Randomized phase 2 study of valproic acid combined with simvastatin and gemcitabine/nab-paclitaxel-based regimens in untreated metastatic pancreatic adenocarcinoma patients: the VESPA trial study protocol

BACKGROUND

Metastatic pancreatic ductal adenocarcinoma (mPDAC) patients have very poor prognosis highlighting the urgent need of novel treatments. In this regard, repurposing non-oncology already-approved drugs might be an attractive strategy to offer more-effective treatment easily tested in clinical trials. Accumulating evidence suggests that epigenetic deregulation is a hallmark of cancer contributing to treatment resistance in several solid tumors, including PDAC. Histone deacetylase inhibitors (HDACi) are epigenetic drugs we have investigated preclinically and clinically as anticancer agents. Valproic acid (VPA) is a generic low-cost anticonvulsant and mood stabilizer with HDAC inhibitory activity, and anticancer properties also demonstrated in PDAC models. Statins use was reported to be associated with lower mortality risk in patients with pancreatic cancer and statins have been shown to have a direct antitumor effect when used alone or in combination therapy. We recently showed capability of VPA/Simvastatin (SIM) combination to potentiate the antitumor activity of gemcitabine/nab-paclitaxel in vitro and in vivo PDAC preclinical models.

METHODS/DESIGN

VESPA is a patient-centric open label randomized multicenter phase-II investigator-initiated trial, evaluating the feasibility, safety, and efficacy of VPA/SIM plus first line gemcitabine/nab-paclitaxel-based regimens (AG or PAXG) (experimental arm) versus chemotherapy alone (standard arm) in mPDAC patients. The study involves Italian and Spanish oncology centers and includes an initial 6-patients safety run-in-phase. A sample size of 240 patients (120 for each arm) was calculated under the hypothesis that the addition of VPA/SIM to gemcitabine and nab-paclitaxel-based regimens may extend progression free survival from 6 to 9 months in the experimental arm. Secondary endpoints are overall survival, response rate, disease control rate, duration of response, CA 19.9 reduction, toxicity, and quality of life. The study includes a patient engagement plan and complementary biomarkers studies on tumor and blood samples.

CONCLUSIONS

VESPA is the first trial evaluating efficacy and safety of two repurposed drugs in oncology such as VPA and SIM, in combination with standard chemotherapy, with the aim of improving mPDAC survival. The study is ongoing. Enrollment started in June 2023 and a total of 63 patients have been enrolled as of June 2024.

TRIAL REGISTRATION

EudraCT number: 2022-004154-63; ClinicalTrials.gov identifier NCT05821556, posted 2023/04/20.

The roles of lncRNAs and miRNAs in pancreatic cancer: a focus on cancer development and progression and their roles as potential biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is among the most penetrative malignancies affecting humans, with mounting incidence prevalence worldwide. This cancer is usually not diagnosed in the early stages. There is also no effective therapy against PDAC, and most patients have chemo-resistance. The combination of these factors causes PDAC to have a poor prognosis, and often patients do not live longer than six months. Because of the failure of conventional therapies, the identification of key biomarkers is crucial in the early diagnosis, treatment, and prognosis of pancreatic cancer. 65% of the human genome encodes ncRNAs. There are different types of ncRNAs that are classified based on their sequence lengths and functions. They play a vital role in replication, transcription, translation, and epigenetic regulation. They also participate in some cellular processes, such as proliferation, differentiation, metabolism, and apoptosis. The roles of ncRNAs as tumor suppressors or oncogenes in the growth of tumors in a variety of tissues, including the pancreas, have been demonstrated in several studies. This study discusses the key roles of some lncRNAs and miRNAs in the growth and advancement of pancreatic carcinoma. Because they are involved not only in the premature identification, chemo-resistance and prognostication, also their roles as potential biomarkers for better management of PDAC patients.

Valproic acid treatment attenuates cisplatin-induced kidney injury by suppressing proximal tubular cell damage

Cisplatin treatment is effective against several types of carcinomas. However, it frequently leads to kidney injury, which warrants effective prevention methods. Sodium valproic acid is a prophylactic drug candidate with a high potential for clinical application against cisplatin-induced kidney injury. Therefore, in this study, we aimed to elucidate the mechanism underlying the prophylactic effect of valproic acid on cisplatin-induced kidney injury in a mouse model and HK2 and PODO cells with cisplatin-induced toxicity. In the mouse model of cisplatin-induced kidney injury, various renal function parameters and tubular damage scores were worsened by cisplatin, but they were significantly improved upon combination with valproic acid. No difference was observed in cisplatin accumulation between the cisplatin-treated and valproic acid-treated groups in whole blood and the kidneys. The mRNA expression levels of proximal tubular damage markers, apoptosis markers, and inflammatory cytokines significantly increased in the cisplatin group 72 h after cisplatin administration but significantly decreased upon combination with valproic acid. In HK2 cells, a human proximal tubular cell line, the cisplatin-induced decrease in cell viability was significantly suppressed by co-treatment with valproic acid. Valproic acid may inhibit cisplatin-induced kidney injury by suppressing apoptosis, inflammatory responses, and glomerular damage throughout the kidneys by suppressing proximal tubular cell damage. However, prospective controlled trials need to evaluate these findings before their practical application.

Synergistic combination of doxorubicin with hydralazine, and disulfiram against MCF-7 breast cancer cell line

Disulfiram and hydralazine have recently been reported to have anti-cancer action, and repositioned to be used as adjuvant in cancer therapy. Chemotherapy combined with other medications, such as those that affect the immune system or epigenetic cell profile, can overcome resistance with fewer adverse effects compared to chemotherapy alone. In the present study, a combination of doxorubicin (DOX) with hydrazine (Hyd) and disulfiram (Dis), as a triple treatment, was evaluated against wild-type and DOX-resistant MCF-7 breast cancer cell line. Both wild-type MCF-7 cell line (MCF-7_WT) and DOX-resistant MCF-7 cell line (MCF-7_DoxR) were treated with different combination ratios of DOX, Dis, and Hyd followed by measuring the cell viability using the MTT assay. Synergism was determined using a combination index, isobologram analysis, and dose-reducing index. The anti-proliferation activity and mechanism of the triple combination were investigated by apoptosis analysis. The results showed a reduction in the IC50 values of DOX in MCF-7_WT cells (from 0.24 μM to 0.012 μM) and MCF-7_DoxR cells (from 1.13 μM to 0.44 μM) when treated with Dis (0.03μM), and Hyd (20μM) combination. Moreover, The triple combination DOX/Hyd/Dis induced significant apoptosis in both MCF-7_WT and MCF-7_DoxR cells compared to DOX alone. The triple combination of DOX, Dis, and Hyd showed a synergistic drugs combination to decrease the DOX dose needed to kill both MCF-7_WT and MCF-7_DoxR cancer cells and enhanced chemosensitivity to DOX.

A comprehensive review on pharmacological applications and drug-induced toxicity of valproic acid

Valproic acid, a branching short chain fatty acid, is a popular drug to treat epilepsy and acts as a mood-stabilizing drug. The obstruction of ion channels and Gamma Amino Butyrate transamino butyrate GABA has been linked to antiepileptic effects. Valproic acid has been characterized as a Histone deacetylase inhibitor, functioning directly transcription of gene levels by blocking the deacetylation of histones and increasing the accessibility of transcription sites. Study has been extensively focused on pharmaceutical activity of valproic acid through various pharmacodynamics activity from absorption, distribution and excretion particularly in patients who are resistant to or intolerant of lithium or carbamazepine, as well as those with mixed mania or rapid cycling.

Prognostic value, immune signature and molecular mechanisms of the APOBEC family members APOBEC1, APOBEC3A, APOBEC3G and APOBEC3H in pancreatic adenocarcinoma

Background: Increasing evidence supports that the APOBEC family is associated with development of a variety of cancers. However, the function of APOBEC1/3A/3G/3H in pancreatic adenocarcinoma (PAAD) is still unclear. Methods: Comprehensive bioinformatic analysis using R (version 3.6.3), TISIDB, Metascape etc. were performed to study the clinicopathological characteristics, prognostic value, immune features and functional mechanisms of the APOBEC1/3A/3G/3H in PAAD. Results: APOBEC1/3A/3G/3H showed significantly elevated expression in PAAD than para-cancerous or normal tissues. Their high expression or amplification were significantly correlated with worse clinicopathological characteristics and prognosis in PAAD patients. In addition, the role of APOBEC1/3A/3G/3H in the immune regulation is diverse and complex, the high expression of APOBEC1 may inhibit the infiltration level of many kinds of immunoreactive tumor-infiltrating cells, which may be an important factor leading to immune escape of PAAD cells. Mechanistically, APOBEC1/3A/3G/3H played an activating role in multiple oncogenic pathways, including the EMT, RAS/MAPK and TSC/mTOR pathways. Moreover, we found that the expression level of APOBEC3G was positively correlated with the sensitivity of gemcitabine and doxorubicin. Conclusion: APOBEC1/3A/3G/3H play an oncogenic role in the development of PAAD and might serve as new biomarkers or therapeutic targets.

Anti-proliferative and Apoptotic Effects of Valproic Acid on HeLa Cells

Background: Valproic acid (VPA), a branched short-chain fatty acid and histone deacetylase (HDAC) inhibitor, has diverse biological activities in human cells, including anti-cancer properties. Objectives: In the present study, we tested the cytotoxicity of VPA on the proliferation, cell cycle, and apoptosis of the human cervical cancer cell line, HeLa. Methods: HeLa cell line was cultured in Dulbecco’s modified eagle medium (DMEM) and the cytotoxicity effect of VPA (at 0 - 100 mM) on the HeLa cell was evaluated, using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay for 3 incubation times (24, 48, and 72 h). The effects of VPA on cell cycle arrest and apoptosis were evaluated, using flow cytometry. In addition, the alterations in the expression of Bax, Bcl-2, p53, and p21 were assessed with real‐time polymerase chain reaction (PCR). Results: Valproic acid reduced the viability of HeLa cells in a concentration- and time-dependent manner, and the IC50 values at 24, 48, and 72 h were 32.06, 21.29, and 14.51 mM, respectively. Further, VPA treatment remarkably increased the apoptosis of HeLa cells and arrested cells at the sub-G1 phase with a significant reduction in G2-M phase populations. The real-time PCR results demonstrated a significant increase in the expression of pro-apoptotic genes, including Bax, p53, and p21, as well as a reduction in the levels of the anti-apoptotic gene, Bcl-2. Conclusions: Valproic acid inhibits the proliferation of the HeLa cell line through the induction of the intrinsic pathway of apoptosis in a p35-dependent manner.

Subtyping for pancreatic cancer precision therapy

The cases of pancreatic cancer and associated deaths are increasing consistently and have become a global health concern. Prevalent intratumoral and intertumoral heterogeneity in pancreatic cancer has been revealed as an important cause of its poor prognosis. However, few precision management strategies have been formulated to treat this complex disease. There is growing evidence supporting the significance of subtyping pancreatic tumors on the basis of their molecular characteristics for improving the accuracy of clinical decision-making on treatment. Here, we summarize the current approaches to classification of pancreatic cancer, and highlight the feasibility and potential defects of their application in precision therapy.

The Class I HDAC Inhibitor Valproic Acid Strongly Potentiates Gemcitabine Efficacy in Pancreatic Cancer by Immune System Activation

Background: Gemcitabine efficacy in pancreatic cancer is often impaired due to limited intracellular uptake and metabolic activation. Epi-drugs target gene expression patterns and represent a promising approach to reverse chemoresistance. In this study, we investigate the chemosensitizing effect of different epi-drugs when combined with gemcitabine in pancreatic cancer. Methods: Mouse KPC3 cells were used for all experiments. Five different epi-drugs were selected for combination therapy: 5-aza-2′-deoxycytidine, hydralazine, mocetinostat, panobinostat, and valproic acid (VPA). Treatment effects were determined by cell proliferation and colony forming assays. Expression of genes were assessed by real-time quantitative PCR. The most promising epi-drug for combination therapy was studied in immune competent mice. Intratumor changes were defined using NanoString PanCancer panel IO360. Results: All epi-drugs, except hydralazine, potentiated the gemcitabine response in KPC3 cells (range decrease IC50 value 1.7−2-fold; p < 0.001). On colony formation, the cytotoxic effect of 0.5 ng/mL gemcitabine was 1.4 to 6.3 times stronger (p < 0.01). Two out of three drug-transporter genes were strongly upregulated following epi-drug treatment (a range fold increase of 17−124 and 9−60 for Slc28a1 and Slc28a3, respectively; all p < 0.001). VPA combined with gemcitabine significantly reduced tumor size with 74% compared to vehicle-treated mice and upregulated expression of immune-related pathways (range pathway score 0.86−1.3). Conclusions: These results provide a strong rationale for combining gemcitabine with VPA treatment. For the first time, we present intratumor changes and show activation of the immune system. Clinical trials are warranted to assess efficacy and safety of this novel combination in pancreatic cancer patients.

Epigenetic landscape of drug responses revealed through large-scale ChIP-seq data analyses

Background

Elucidating the modes of action (MoAs) of drugs and drug candidate compounds is critical for guiding translation from drug discovery to clinical application. Despite the development of several data-driven approaches for predicting chemical–disease associations, the molecular cues that organize the epigenetic landscape of drug responses remain poorly understood.

Results

With the use of a computational method, we attempted to elucidate the epigenetic landscape of drug responses, in terms of transcription factors (TFs), through large-scale ChIP-seq data analyses. In the algorithm, we systematically identified TFs that regulate the expression of chemically induced genes by integrating transcriptome data from chemical induction experiments and almost all publicly available ChIP-seq data (consisting of 13,558 experiments). By relating the resultant chemical–TF associations to a repository of associated proteins for a wide range of diseases, we made a comprehensive prediction of chemical–TF–disease associations, which could then be used to account for drug MoAs. Using this approach, we predicted that: (1) cisplatin promotes the anti-tumor activity of TP53 family members but suppresses the cancer-inducing function of MYCs; (2) inhibition of RELA and E2F1 is pivotal for leflunomide to exhibit antiproliferative activity; and (3) CHD8 mediates valproic acid-induced autism.

Conclusions

Our proposed approach has the potential to elucidate the MoAs for both approved drugs and candidate compounds from an epigenetic perspective, thereby revealing new therapeutic targets, and to guide the discovery of unexpected therapeutic effects, side effects, and novel targets and actions.

Detailed Molecular Mechanisms Involved in Drug-Induced Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis: An Update

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are some of the biggest public health challenges due to their spread and increasing incidence around the world. NAFLD is characterized by intrahepatic lipid deposition, accompanied by dyslipidemia, hypertension, and insulin resistance, leading to more serious complications. Among the various causes, drug administration for the treatment of numerous kinds of diseases, such as antiarrhythmic and antihypertensive drugs, promotes the onset and progression of steatosis, causing drug-induced hepatic steatosis (DIHS). Here, we reviewed in detail the major classes of drugs that cause DIHS and the specific molecular mechanisms involved in these processes. Eight classes of drugs, among the most used for the treatment of common pathologies, were considered. The most diffused mechanism whereby drugs can induce NAFLD/NASH is interfering with mitochondrial activity, inhibiting fatty acid oxidation, but other pathways involved in lipid homeostasis are also affected. PubMed research was performed to obtain significant papers published up to November 2021. The key words included the class of drugs, or the specific compound, combined with steatosis, nonalcoholic steatohepatitis, fibrosis, fatty liver and hepatic lipid deposition. Additional information was found in the citations listed in other papers, when they were not displayed in the original search.

MiRNA-375 inhibits retinoblastoma progression through targeting ERBB2 and inhibiting MAPK1/MAPK3 signalling pathway

BACKGROUND

Increasing evidence has shown that the dysregulation of miRNAs is involved in the pathogenesis of retinoblastoma (RB). This present study was aimed to investigate the significance of miR-375 in RB progression, and the underlying mechanism.

MATERIALS AND METHODS

The miR-375 expression was detected by RT-PCR. CCK-8 assay and transwell assays were used to measure RB cell viability, migration, and invasion. The downstream gene of miR-375 was verified by luciferase reporter assay. Western blot was applied to detect the related proteins of MAPK1/MAPK3 signalling pathway.

RESULTS

MiR-375 was decreased significantly in RB tissues, and its down-regulation was associated with the poor prognosis of RB patients. Over-expression of miR-375 inhibited RB cell proliferation, migration, and invasion. More importantly, miR-375 modulated ERBB2 expression negatively, and ERBB2 was confirmed as the target of miR-375. Moreover, ERBB2 overturned the inhibitory effect of miR-375 mimic on the progression of RB. MiR-375 mimic suppressed RB progression via inhibiting the activation of MAPK1/MAPK3 signalling pathway.

CONCLUSIONS

MiR-375 inhibited RB progression through targeting ERBB2 and suppressing MAPK1/MAPK3 signalling pathway, which might be a new target for the clinical treatment strategy.

Hidden pharmacological activities of valproic acid: A new insight

Valproic acid (VPA) is an approved drug for managing epileptic seizures, bipolar disorders, and migraine. VPA has been shown to elevate the level of gamma-aminobutyric acid (GABA) in the brain through competitive inhibition of GABA transaminase, thus promoting the availability of synaptic GABA and facilitating GABA-mediated responses. VPA, which is a small chain of fatty acids, prevents histone deacetylases (HDACs). HDACs play a crucial role in chromatin remodeling and gene expression through posttranslational changes of chromatin-associated histones. Recent studies reported a possible effect of VPA against particular types of cancers. This effect was partially attributed to its role in regulating epigenetic modifications through the inhibition of HDACs, which affect the expression of genes associated with cell cycle control, cellular differentiation, and apoptosis. In this review, we summarize the current information on the actions of VPA in diseases such as diabetes mellitus, kidney disorders, neurodegenerative diseases, muscular dystrophy, and cardiovascular disorders.

miR‑125a‑5p and miR‑7 inhibits the proliferation, migration and invasion of vascular smooth muscle cell by targeting EGFR

The ectopic proliferation, migration and invasion of vascular smooth muscle cells (VSMCs) contributes to the progression of various human vascular diseases. Accumulating evidence has demonstrated that microRNAs (miRs) exert vital functions in the proliferation and invasion of VSMCs. The current study aimed to elucidate the functions of miR-125a-5p and miR-7 in VSMCs and investigate the associated molecular mechanisms. The results of EdU and reverse transcription-quantitative PCR assays revealed that platelet-derived growth factor (PDGF)-BB enhanced the proliferation of VSMCs and significantly reduced the expression of miR-125a-5p and miR-7. miR-125a-5p or miR-7 overexpression significantly ameliorated PDGF-BB-induced proliferation, migration and invasion of VSMCs. Furthermore, the results demonstrated that epidermal growth factor receptor (EGFR) may be a target mRNA of miR-125a-5p and miR-7 in VSMCs. The results of western blot analysis indicated that co-transfection of miR-125a-5p mimics or miR-7 mimics distinctly decreased the protein expression of EGFR in EGFR-overexpressed VSMCs. Moreover, rescue experiments indicated that EGFR overexpression alleviated the suppressive impact of the miR-125a-5p and miR-7 s on the growth, migration and invasion of VSMCs. In conclusion, the current study identified that miR-125a-5p and miR-7 repressed the growth, migration and invasion of PDGF-BB-stimulated VSMCs by, at least partially, targeting EGFR. The current study verified that miR-125a-5p and miR-7 may be used as feasible therapeutic targets for cardiovascular diseases.

Valproic Acid and Breast Cancer: State of the Art in 2021

Valproic acid (2-propylpentanoic acid, VPA) is a short-chain fatty acid, a member of the group of histone deacetylase inhibitors (HDIs). VPA has been successfully used in the treatment of epilepsy, bipolar disorders, and schizophrenia for over 50 years. Numerous in vitro and in vivo pre-clinical studies suggest that this well-known anticonvulsant drug significantly inhibits cancer cell proliferation by modulating multiple signaling pathways. Breast cancer (BC) is the most common malignancy affecting women worldwide. Despite significant progress in the treatment of BC, serious adverse effects, high toxicity to normal cells, and the occurrence of multi-drug resistance (MDR) still limit the effective therapy of BC patients. Thus, new agents which improve the effectiveness of currently used methods, decrease the emergence of MDR, and increase disease-free survival are highly needed. This review focuses on in vitro and in vivo experimental data on VPA, applied individually or in combination with other anti-cancer agents, in the treatment of different histological subtypes of BC.

Three Immune-Related Prognostic mRNAs as Therapeutic Targets for Pancreatic Cancer

Objective: Pancreatic cancer is a highly lethal malignancy globally. This study aimed to probe and validate immune-related prognostic mRNAs as therapeutic targets for pancreatic cancer.

Methods: Gene transcriptome data of pancreatic cancer and normal pancreas were retrieved from TCGA-GTEx projects. Two thousand four hundred and ninety-eight immune-related genes were obtained from the IMMUPORT database. Abnormally expressed immune-related genes were then identified. Under univariate and multivariate cox models, a gene signature was constructed. Its predictive efficacy was assessed via ROCs. The interactions between the 21 genes were analyzed by Spearson analysis and PPI network. Using the GEPIA and The Human Protein Atlas databases, their expression and prognostic value were evaluated. The TIMER database was utilized to determine the relationships between MET, OAS1, and OASL mRNAs and immune infiltrates. Finally, their mRNA expression was externally verified in the GSE15471 and GSE62452 datasets.

Results: An immune-related 21-gene signature was developed for predicting patients' prognosis. Following verification, this signature exhibited the well predictive performance. There were physical and functional interactions between them. MET, OAS1, and OASL mRNAs were all up-regulated in pancreatic cancer and associated with unfavorable prognosis. They showed strong correlations with tumor progression. Furthermore, the three mRNAs were distinctly associated with immune infiltrates. Their up-regulation was confirmed in the two external datasets.

Conclusion: These findings identified three immune-related prognostic mRNAs MET, OAS1, and OASL, which may assist clinicians to choose targets for immunotherapy and make personalized treatment strategy for pancreatic cancer patients.

Apoptotic effects of valproic acid on miR-34a, miR-520h and HDAC1 gene in breast cancer

Identifying miRNAs involved in cancer and devising strategies to control their expression is a new therapeutic approach. Valproic acid (VPA) has attracted a lot of interest in cancer research. We evaluated the impact of VPA on the expression of miR-34a, miR-520h, and their target gene histone deacetylase 1 (HDAC1), as well as their relationship with apoptosis in breast cancer. First, through bioinformatics analyses, the possible target genes of miR-34a and miR-520h and their roles in apoptosis regulation were investigated. Then, miR-34a, miR-520h, and HDAC1 gene expression in tissues of breast cancer patients were determined using the qRT-PCR method. The anticancer impact of VPA on apoptosis and the expression levels of miR-34a, miR-520h, and HDAC1 gene were measured in MCF-7 and MDA-MB-231 cell lines. The bioinformatics analyses indicated that miR-34a and miR-520h might make a unique contribution in regulating the apoptosis pathway. The relative expression of miR-34a and miR-520h significantly decreased in cancer tissues, while the relative expression of HDAC1 increased. In the in vitro study, VPA led to apoptosis induction and increased lipid peroxidation products in breast cancer cells. Moreover, VPA increased the expression of miR- 34a and miR-520h and decreased HDAC1 expression in MCF-7 cells. In MDA-MB-231 cells, VPA decreased the expression of these miRNAs and increased the expression of HDAC1. It can be concluded that miR-34a and miR-520h are implicated in the apoptosis pathways, and thus, VPA can recruit as a possible option in breast cancer research due to its interference with epigenetic processes.

Photosensitizer Nanoparticles Boost Photodynamic Therapy for Pancreatic Cancer Treatment

Patients with pancreatic cancer (PCa) have a poor prognosis apart from the few suitable for surgery. Photodynamic therapy (PDT) is a minimally invasive treatment modality whose efficacy and safety in treating unresectable localized PCa have been corroborated in clinic. Yet, it suffers from certain limitations during clinical exploitation, including insufficient photosensitizers (PSs) delivery, tumor-oxygenation dependency, and treatment escape of aggressive tumors. To overcome these obstacles, an increasing number of researchers are currently on a quest to develop photosensitizer nanoparticles (NPs) by the use of a variety of nanocarrier systems to improve cellular uptake and biodistribution of photosensitizers. Encapsulation of PSs with NPs endows them significantly higher accumulation within PCa tumors due to the increased solubility and stability in blood circulation. A number of approaches have been explored to produce NPs co-delivering multi-agents affording PDT-based synergistic therapies for improved response rates and durability of response after treatment. This review provides an overview of available data regarding the design, methodology, and oncological outcome of the innovative NPs-based PDT of PCa.

Epigenetic Effects Mediated by Antiepileptic Drugs and their Potential Application

An epigenetic effect mainly refers to a heritable modulation in gene expression in the short term but does not involve alterations in the DNA itself. Epigenetic molecular mechanisms include DNA methylation, histone modification, and untranslated RNA regulation. Antiepileptic drugs have drawn attention to biological and translational medicine because their impact on epigenetic mechanisms will lead to the identification of novel biomarkers and possible therapeutic strategies for the prevention and treatment of various diseases ranging from neuropsychological disorders to cancers and other chronic conditions. However, these transcriptional and posttranscriptional alterations can also result in adverse reactions and toxicity in vitro and in vivo. Hence, in this review, we focus on recent findings showing epigenetic processes mediated by antiepileptic drugs to elucidate their application in medical experiments and shed light on epigenetic research for medicinal purposes.

Refocusing the Use of Psychiatric Drugs for Treatment of Gastrointestinal Cancers

Gastrointestinal cancers (GICs) are the most common human tumors worldwide. Treatments have limited effects, and increasing global cancer burden makes it necessary to investigate alternative strategies such as drug repurposing. Interestingly, it has been found that psychiatric drugs (PDs) are promising as a new generation of cancer chemotherapies due to their anti-neoplastic properties. This review compiles the state of the art about how PDs have been redirected for cancer therapeutics in GICs. PDs, especially anti-psychotics, anti-depressants and anti-epileptic drugs, have shown effects on cell viability, cell growth, inhibition of proliferation (cell cycle arrest), apoptosis promotion by caspases activation or cytochrome C release, production of reactive oxygen species (ROS) and nuclear fragmentation over esophageal, gastric, colorectal, liver and pancreatic cancers. Additionally, PDs can inhibit neovascularization, invasion and metastasis in a dose-dependent manner. Moreover, they can induce chemosensibilization to 5-fluorouracil and cisplatin and can act synergistically with anti-neoplastic drugs such as gemcitabine, paclitaxel and oxaliplatin. All anti-cancer activities are given by activation or inhibition of pathways such as HDAC1/PTEN/Akt, EGFR/ErbB2/ErbB3, and PI3K/Akt; PI3K-AK-mTOR, HDAC1/PTEN/Akt; Wnt/β-catenin. Further investigations and clinical trials are needed to elucidate all molecular mechanisms involved on anti-cancer activities as well as adverse effects on patients.

Valproic Acid Sensitizes Glioma Cells to Luteolin Through Induction of Apoptosis and Autophagy via Akt Signaling

Glioma is a highly malignant type of intracranial tumor with a poor prognosis resulting from traditional chemo-resistance with temozolomide (TMZ). Luteolin has been detected to exert limited anti-tumor effects on gliomas, while valproic acid (VPA) is a common chemotherapy sensitizer in the treatment of tumors. In this study, three glioma cell lines including U251, LN229 and SNB19 were selected for evaluation of combined anti-tumor effects of VPA and luteolin via Cell Counting Kit-8 (CCK-8) assay, colony formation assay, wound-healing assay, flow cytometry and western blot assay. The results disclosed that VPA sensitized glioma cells to luteolin by repressing cell viability, colony formation and migration. Mechanically, VPA boosted cellular apoptosis and cell-cycle arrest by increased level of cleaved caspase-3/caspase-3, cleaved PARP/PARP and Bax/Bcl-2. In addition, VPA also facilitated cellular autophagy via the decline of p62, p-Akt/Akt and the accumulation of LC3-II. These findings suggested that VPA enhanced the anticancer effects of luteolin by strengthening apoptosis and autophagy via Akt signaling, which could be adopted as a novel therapy for glioma.

Combination of Arsenic Trioxide and Valproic Acid Efficiently Inhibits Growth of Lung Cancer Cells via G2/M-Phase Arrest and Apoptotic Cell Death

Arsenic trioxide (ATO; As₂O₃) has anti-cancer effects in various solid tumors as well as hematological malignancy. Valproic acid (VPA), which is known to be a histone deacetylase inhibitor, has also anti-cancer properties in several cancer cells including lung cancer cells. Combined treatment of ATO and VPA (ATO/VPA) could synergistically enhance anti-cancer effects and reduce ATO toxicity ATO. In this study, the combined anti-cancer effects of ATO and VPA (ATO/VPA) was investigated in NCI-H460 and NCI-H1299 lung cancer cells in vitro and in vivo. A combination of 3 μM ATO and 3 mM VPA (ATO/VPA) strongly inhibited the growths of both lung cancer cell types. DNA flow cytometry indicated that ATO/VPA significantly induced G2/M-phase arrest in both cell lines. In addition, ATO/VPA strongly increased the percentages of sub-G1 cells and annexin V-FITC positive cells in both cells. However, lactate dehydrogenase (LDH) release from cells was not increased in ATO/VPA-treated cells. In addition, ATO/VPA increased apoptosis in both cell types, accompanied by loss of mitochondrial membrane potential (MMP, ∆Ψm), activation of caspases, and cleavage of anti-poly ADP ribose polymerase-1. Moreover, a pan-caspase inhibitor, Z-VAD, significantly reduced apoptotic cell death induced by ATO/VPA. In the xenograft model, ATO/VPA synergistically inhibited growth of NCI-H460-derived xenograft tumors. In conclusion, the combination of ATO/VPA effectively inhibited the growth of lung cancer cells through G2/M-phase arrest and apoptotic cell death, and had a synergistic antitumor effect in vivo.

Mesenchymal stem cell-derived exosomes protect beta cells against hypoxia-induced apoptosis via miR-21 by alleviating ER stress and inhibiting p38 MAPK phosphorylation

Background

Hypoxia is a major cause of beta cell death and dysfunction after transplantation. The aim of this study was to investigate the effect of exosomes derived from mesenchymal stem cells (MSCs) on beta cells under hypoxic conditions and the potential underlying mechanisms.

Methods

Exosomes were isolated from the conditioned medium of human umbilical cord MSCs and identified by WB, NTA, and transmission electron microscopy. Beta cells (βTC-6) were cultured in serum-free medium in the presence or absence of exosomes under 2% oxygen conditions. Cell viability and apoptosis were analysed with a CCK-8 assay and a flow cytometry-based annexin V-FITC/PI apoptosis detection kit, respectively. Endoplasmic reticulum stress (ER stress) proteins and apoptosis-related proteins were detected by the WB method. MiRNAs contained in MSC exosomes were determined by Illumina HiSeq, and treatment with specific miRNA mimics or inhibitors of the most abundant miRNAs was used to reveal the underlying mechanism of exosomes.

Results

Exosomes derived from MSC-conditioned culture medium were 40–100 nm in diameter and expressed the exosome markers CD9, CD63, CD81, HSP70, and Flotillin 1, as well as the MSC markers CD73, CD90, and CD105. Hypoxia significantly induced beta cell apoptosis, while MSC exosomes remarkably improved beta cell survival. The WB results showed that ER stress-related proteins, including GRP78, GRP94, p-eIF2α and CHOP, and the apoptosis-related proteins cleaved caspase 3 and PARP, were upregulated under hypoxic conditions but were inhibited by MSC exosomes. Moreover, the p38 MAPK signalling pathway was activated by hypoxia and was inhibited by MSC exosomes. The Illumina HiSeq results show that MSC exosomes were rich in miR-21, let-7 g, miR-1246, miR-381, and miR-100. After transfection with miRNA mimics, the viability of beta cells under hypoxia was increased significantly by miR-21 mimic, and the p38 MAPK and ER stress-related proteins in beta cells were downregulated. These changes were reversed after exosomes were pretreated with miR-21 inhibitor.

Conclusions

Exosomes derived from MSCs could protect beta cells against apoptosis induced by hypoxia, largely by carrying miR-21, alleviating ER stress and inhibiting p38 MAPK signalling. This result indicated that MSC exosomes might improve encapsulated islet survival and benefit diabetes patients.

Sparse Graph Regularization Non-Negative Matrix Factorization Based on Huber Loss Model for Cancer Data Analysis

Non-negative matrix factorization (NMF) is a matrix decomposition method based on the square loss function. To exploit cancer information, cancer gene expression data often uses the NMF method to reduce dimensionality. Gene expression data usually have some noise and outliers, while the original NMF loss function is very sensitive to non-Gaussian noise. To improve the robustness and clustering performance of the algorithm, we propose a sparse graph regularization NMF based on Huber loss model for cancer data analysis (Huber-SGNMF). Huber loss is a function between L₁-norm and L₂-norm that can effectively handle non-Gaussian noise and outliers. Taking into account the sparsity matrix and data geometry information, sparse penalty and graph regularization terms are introduced into the model to enhance matrix sparsity and capture data manifold structure. Before the experiment, we first analyzed the robustness of Huber-SGNMF and other models. Experiments on The Cancer Genome Atlas (TCGA) data have shown that Huber-SGNMF performs better than other most advanced methods in sample clustering and differentially expressed gene selection.

Similar Population of CD133+ and DDX4+ VSEL-Like Stem Cells Sorted from Human Embryonic Stem Cell, Ovarian, and Ovarian Cancer Ascites Cell Cultures: The Real Embryonic Stem Cells?

A population of small stem cells with diameters of up to 5 μm resembling very small embryonic-like stem cells (VSELs) were sorted from human embryonic stem cell (hESC) cultures using magnetic-activated cell sorting (MACS) based on the expression of a stem-cell-related marker prominin-1 (CD133). These VSEL-like stem cells had nuclei that almost filled the whole cell volume and expressed stem-cell-related markers (CD133, SSEA-4) and markers of germinal lineage (DDX4/VASA, PRDM14). They were comparable to similar populations of small stem cells sorted from cell cultures of normal ovaries and were the predominant cells in ascites of recurrent ovarian cancer. The sorted populations of CD133+ VSEL-like stem cells were quiescent in vitro, except for ascites, and were highly activated after exposure to valproic acid and follicle-stimulating hormone (FSH), indicating a new tool to study these cells in vitro. These VSEL-like stem cells spontaneously formed clusters resembling tumour-like structures or grew into larger, oocyte-like cells and were differentiated in vitro into adipogenic, osteogenic and neural lineages after sorting. We propose the population of VSEL-like stem cells from hESC cultures as potential original embryonic stem cells, which are present in the human embryo, persist in adult human ovaries from the embryonic period of life and are involved in cancer manifestation.